Method of and arrangement for receiving short waves



April 13, 1937. VQN ARDENNE 2,077,289

I METHOD OF AND ARRANGEMENT FO R RECEIVING SHORT WAVES Filed Feb. 5, 1934 JnVen/or:

Patented Apr. 13, 1937 UNITED STATES PATENT OFFICE METHOD OF AND ARRANGEMENT FOR RECEIVING SHORT WAVES Manfred von Ardenne, Berlin, Germany Application February 5, 1934, Serial No. 709,707 In Germany February 15, 1933 2 Claims.

tial when normal radio waves are rectified.

By careful investigation of the frequency dependency of the efiiciency of the rectifier the applicant has been able to ascertain the reasons for the low frequency, not occurring in the normal radio frequency range, and to find means for remedying the same.

Experiments of this nature may be conducted in such fashion that one and the same highfrequency amplitude is conducted to a tube rectifying connection system at a frequency varied between A=3 meters and 200 meters, and the potential rectifying effect is measured in the anode circuit. By such measures the applicant has found that the rectification of short waves is considerably better if relatively powerful currents are eifected in the rectifier circuits. According to the invention, this is effected by employing small resistances in the anode circuits.

Experiments have provided the following results:

In connection with grid-leak rectification experiments have shown that the efficiency may be considerably improved by the use of small grid leakage resistances or by the use of leakage chokes in the grid circuit. The frequency dependency itself appears not to follow a simple rule in this connection, in the range of higher frequencies.

The grid current, the ascending curve of which is employed for the grid-leak rectification, occurs in the potential ranges which are employed in practice by reason of extremely slow electrons having speeds which are less than 1 volt. The electrons assume higher speeds not until the electrons have passed the grid, 1. e., at a time when control has already taken place. As long as the electron speeds are so small the time in which an electron is passing from cathode to anode is such that the same is greater, or may be greater, than the period, for example, of a 7-meter oscillation. From the influence exerted by the duration of passage of the electrons, which cannot be ignored in the rectification, there results the frequency dependency of the rectification in the frequency range above stated.

After having found out the reasons for this frequency dependency in accordance with the invention for improving the efficiency of the grid leak rectification for short waves:

There is used strong positive grid potential and small grid leakage resistances in the order of 10 ohms, or the use of leakage chokes of small ohmic resistance.

When employing connection systems having resistances with the value and arrangement as set forth in accordance with the invention it is possible to produce receivers for short waves,

and more particularly waves of less than 10 meters (preferably for television purposes), which have an adequate sensitiveness, even without intermediate frequency.

In the drawing there is shown by way of an example a form of embodiment of receiving and rectifying systems for anode-bend rectification, the connecting elements in the working circuits having the values according to the invention. The single parts are the rectifier tube I with the cathode 2, the grid 3 and the anode 4.

Between the grid and the cathode there is provided the oscillatory circuit 5, which comprises the self-inductance 6 and the variable capacity 1, whereby the grid is tapped over a resistance 8, which in accordance with the invention is in the order of 10 ohms, and in order to obtain the smallest possible damping effect there is connected in parallel with the leakage resistance a capacity 9. The battery l0 serves to produce a strong positive potential for the grid.

In the outer anode circuit there is connected a resistance ll. Coupling is performed through.

the medium of a condenser I2.

I claim:

1. In a tube for rectifying short waves, more particularly for waves of less than 10 meters, using grid leak rectification, a cathode, a grid and an anode, said grid connected to a relatively high positive potential over a relatively small grid leak resistance in order to make the time the electrons take to pass the distance between the electrodes shorter than a period of the high frequency to be rectified.

2. In a tube for rectifying short waves, more particularly for waves of less than 10 meters, using grid leak rectification, a cathode, a grid and an anode, said grid connected to a relatively high positive potential over a grid leakage choke coil having small ohmic resistance, in order to make the time the electrons take to pass the distance between the electrodes shorter than a period of the high frequency to be rectified.

MANFRED VON ARDETNNE, 

